Not saying anything at all? Do you need someone to hold your hand?
Look Alice, why don't you give an explanation of the hormonal regulation of breast development? What's wrong? Cat got your tongue or is your daily dosage of machismo from looking at yourself in the mirror too high?
Alright, it's time you realize that you are a fucking ingrate. You have no practical education and/or experience whatsoever, therefore you have absolutely no right to even begin commenting on the ontogeny, physiology and factors that that influence gynecomastia.
The hormones that affect growth and differentiation of breast tissue are estrogen, progesterone, prolactin, GH and IGF-1. It is through their respective receptors where estrogen promotes duct growth the progesterone supports aveolar development. Neither estrogen nor progesterone by themselves can sustain breast development without anterior pituitary hormones, GH and IGF-1. Furthermore, GH may result in an increase of IGF-1 mRNA at the mammary gland which locally promotes tissue growth. Last but not least is prolactin which has a similar relationship like estrogen/progesterone to GH/IGF-1 where it stimulates epithelial cell proliferation and enhances lobulo alveolar differentiation only in the presence of estrogen and progesterone respectively.
I'm sure you are looking for a dictionary by now. Don't panic as I will do my best to summarize my previous paragraph in a less intellectual fashion so that you can better comprehend the key points and apply it in a practical manner.
Therefore, the most common scenarios for the development of gynecomastia in men may be a result of supraphsyiological levels of estrogen/progesterone, physiological levels of estrogen/progesterone in the presence of decreased androgens or physiological levels of estrogen, progesterone and androgens in the presence of elevated GH/IGF-1.
Is that starting to make sense? Perhaps you need an example such as the usage of Nolvadex in the treatment of gynecomastia. Hopefully, by now you can recognize how estrogen and IGF-1 are related in regards to gynecomastia as well as the effects of Nolvadex on estrogen and IGF-1. I think a relatively valid conclusion that Nolvadex inhibits the stimulation of ductal growth from estrogen and concurrently inhibits the role of IGF-1 in stromal/ductal hyperplasia.
In conclusion, all you need in order to diagnose the origin versus playing the guessing game is to have blood work performed. You do have common sense don't you?
Happy Holidays,
Jenetic